Annealing-furnace



F. S.- KOCHENDORFER AND B. E. BALDUR ANNEALING FURNACE.

APPLICATION Flu-:o SEPT. lo. 191s.

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UNITED STATES' FREDERIC S. KOCHENDORFER, 0F CHICAGO, AND BRUNO` E. BALDUF, OF CICEBO PATENT? OFFICE.

ILLINOIS, ASSIGNOBS TO WESTERN ELECTRIC COMPANY, INCORPORATED, 0F NEW. YORK, N. Y., A CORPORATION OF NEW YORK.

ANNEALINGLFUBNACE.

Specification of Letters Ilatent. Patented Sept. 14, 1920.

i Application led' September 10, 1918. Serial No. 253,386.

This invention relates to annealing fur naces, and more particularly to a furnace for annealing materials having a bright surface.

The object of this invention is to provide an annealing furnace for bright surfaced materials, by means of which such materials may be rapidly and thoroughlyv annealed without oxidizing or without having the surfaces marredby water spots.

In accordance with the general features of this invention, there is provided an annealing furnace comprising generally an annealing tube divided into zones for anneal-v ing and cooling the material and thoroughly drying it before exposing it to the atmosphere. More' specifically, the furnace of this invention comprises a tube which opens into a water tank at its receivin end and into the air at its discharge end. urroun'ding the tube intermediate its ends are a heating means lfor raising the temperature of the material to be annealed and cooling means by means of which the temperature of the annealed materialV is lowered below the temperature of oxidation before it reaches the discharge end of the tube. Su-

perheated stea'm is introduced into the tube at the receivin end,and the discharge end of the tube is ent over. so that the steam will -seal the tube against ingress of air.

The steam introduced into the tube at the.

receiving end is condensed by the cooling means surrounding the tube and drawn off at the discharge end.

In the drawings illustrating this invention:

Figure l is a view in 'side elevation of an annealing furnace made in accordance with this invention, and y Fig. 2 is a fragmentary cross-sectional View illustrating the parts shown' in Fig. 1. As shown in the drawings 5 designates a tube of suitable heat resisting material which has one end 6 opening into a water seal 7. At its opposite end S the tube 5 is inclined downwardly and is open to the air. Surrounding the tube 5 near the end 7 is a heating element 9 comprising a .wall 10 of fire clay, whichV wall is also surrounded by a wall 11 of heat resisting material suchl as that known in the trade as .Sil-O-Cel. Located in the chamber between the walls 10 and 11 are a plurality of gas burners 13-13 by means of which the interior of the tube 5 may begraised to a temperature sulicient to anneal the material passing through it.

y Beyond the heating element 9 and surrounding the major portion of the tube 5 is a water jacket l5 having inlet and outlet pipes 16 and 17.

At the receiving end of the tube 5 is a steam inlet 18 connected with a superheatling coil 19 located within the heating chamber.

Extending through the tube 5 and beneath a supporting frame v25 is an endless belt carrier 26 driven by means of a. motor 27 and adapted to'carr the material to be annealed through the tu e 5. In the particular application of this invention illustrated, the

carrier 26 is shown as conveying metal spools 28 through the tube 5. A

An asbestos covering 30 may be placed around the tube 5 at the receiving end thereof and an opening 3l isprovided through this asbestos covering and the tube 5 for receiving la thermo couple. In the operation of the apparatus of this invention metalk spools containing bright copper wire or other material may be inserted into the tube 5 through the water seal -7 into which the end 6yof the tube opens, and the movement of the conveyer 26 will draw these spools up into and through the tube- 5 to the discharge end 8.V As the spools are thus passed through the tube 5 vtheir contents will irst be heated to an annealing temperature bytheir passage through theheating element'lO. As they leavel the heating element they will enter the zone surrounded by the` water jacket 15, through which water is continually flowing, and will gradually be cooled as they approach the end of the tube 5 to a temperature which is lower than the temperature at which the copper would ordinarily be oxidized. The superheated steam which is introduced into vvo of the moisture from the spools as they leave the water seal 7 and this steam will be gradually cooled as it comes into contact with the zone surrounded by the water jacket 15 until it is practically all condensed by the time that it reaches the open end of the tube 5. The pressure of this steam, however, throughout the tube will, due to the fact that the discharge end of the tube is `bent downwardly, be sufficient to exclude the .air therefrom up to a point beyond the zone of thewater jacket 15, at which point the spools will be cooled to a point'where they will not oxidize upon contact with the air. The water of condensation may be drawn out through a drain pipe 36 adjacent the open end of the tube 5.

The advantages of this construction are that oxidation or discoloring of the wire is avoided by reason of the fact that the wire is absolutely prevented from` contact with the atmosphere until it has been cooled below a temperature at which it would ordinarily oxidize or discolor, and because of the fact that the wire or material is thoroughly dried before it reaches the open end of the tube itwill not be discolored or spotted, due to water remaining on it after it has passed through the cooling stage. The use of steam for sealing the discharge end of the tube simplifies the operation of the furnace and permits'of a practically uninterrupted operation of the mechanism.

What is claimed is: v 1. In an annealing lfurnace, a tube through which the material to be annealed is passed, a water seal into which one end of said tube opens` the other end of said tube opening into the air, means for sealing the greater portion of the tubular area from the outside air, means for raising the material to an annealing temperature in one portion of the sealed area, and means for cooling said material below the temperature of oxidation in another portion of said sealed area.

2. In an annealing `furnace, a tube through which the material to be annealed 1s passed, a water seal into which one end of the tube opens, the other end of said tube opening into the air` means for sealing the greater portion of the tubular area from the outside air, a heating element adjacent one portion of said tube for raising the material to an annealing temperature in one -portion 'of the sealed area, and a cooling chamber surrounding said tube to cool said material below the temperatr re of oxidation in another portion of the sealed area.

3. In an annealing furnace, a tube through which the material to be annealed is passed, a water seal into which one end of the tube opens the other end-of said tube opening into the air, means located at one end of the tube for excluding the air from ,i the greater portion of the tubular area, a

heatingchamber located at one end of the y tube for raising the material to anannealing temperature, and a cooling chamber surrounding said tube at the opposite end thereof to cool the annealed material below the temperature of oxidation.

4. In an annealing furnace, a tube through which the material to be annealed is passed, a water seal into which the receiving end of said tube opens, the discharge end of said tube opening into the air, a heating chamber located near the receiving end ot' said tube` a cooling chamber surrounding said tube beyond the heating chamber, and means for introducing steam into said tube to seal it against the air.

5. In an annealing furnace, a tube through which the material to be annealedv rial and seal said tube against ingress of air.

. 6. In an annealing furnace, a tube through which the material to be annealed is passed, a water seal into which the receiving end of the tube opens, the discharge end of said tube opening into the air, a heat-v ing chamber surrounding the tube near the receiving end thereof, a 'cooling` chamber surrounding said tube beyond the heating chamber, means for introducing superheated steam into said tube to be led' past said cooling chamber, and means for drawin off the water of condensation from said tu e. Y 7. In an annealing furnace, a tube through -which the material to be annealed is passed, a water seal into whiclrthe receiving end of said tube opens, the discharge end of said tube being inclined downwardly and opening into the air, heating and cooling chambers surrounding said tube, and means for passing steam through said tube from the receiving to the discharge end.

. In witness whereof, we hereunto subscribe 4our names this 24th day of August-A. D., 

